138 HUNTINGTON. 



planted, at somewhat varying levels as we shall see, upon the 

 stem-bronchus of the right side, its appearance being fore-shad- 

 owed by the arrangement of the arterial branch ( 6) of the bilat- 

 eral hyparterial tree of Taxidea. 



IV. Dicotyles torquatus — Collared Peccary. 



Corrosion of bronchial system and pulmonary artery. Co- 

 lumbia University Museum, No. 1258. PL XIX. 



This preparation exhibits a good type of the further modifica- 

 tions encountered among the Artiodactyla. 



On the left side the entire bronchial distribution is hyparterial, 

 the cephalic trunk A dividing into an apical (A'^ and a lateral 

 {A") branch. 



On the right side, as in Canis, the trunk A disappears by 

 complete segmentation of its secondary branches, and the pul- 

 monary artery crosses dorso-laterad, cephalad of the origin of 

 A" from the stem-bronchus. 



A' has shifted its point of origin, compared with Canis^ 

 further cephalad and appears as a lateral branch derived from 

 the right side of the trachea. 



The distribution of the caudal trunk in symmetrical. The 

 stem-bronchus appears as an especially distinct structure, gradu- 

 ally diminishing in calibre in descent. B' appears as its first 

 lateral branch caudad of the origin of A on the left and A" on 

 the right side. 



The cardiac bronchus and corresponding artery occupy the 

 same position as in Canis. 



V. Myrmecophaga jubata — Great Ant-Eater. 



Corrosion preparation of bronchial system and pulmonary 

 artery. Columbia University Museum, No. 479. PL XX. 



A further advance in the migration cephalad of the right 

 cephalic trunk A is noted in this preparation. 



